Telephone-signal apparatus



(No Model.)

J. A. MoGOY.

TELEPHONE SIGNAL APPARATUS.

Patented Aug. 16, 1881.

Wit E5555.

ahinglml. u. c.

NITED STATES PATENT OFFICE.

JOHN A. MCCOY, OF FALL RIVER, ASSIGNOR TO CHAS. W. CLIFFORD, TRUSTEE, OFNEW BEDFORD, MASSACHUSETTS.

TELEPHONE-SIGNAL APPARATUS.

SPECIFICATION forming part of Letters Patent No. 245,648, dated August16, 1881.

Application filed March 29, 1880. (No model.)

To all whom it may concern:

Be it known that I, JOHN A. MCCOY, of

Fall River, county of Bristol, State of Massachusetts, have invented anImprovement in Telephone-Signal Apparatus, of which the followingdescription, in connection with the accompanying drawings, is aspecification.

My invention relates to telephone-signals, and has for its object toenable an operator to call any desired signal-bell on a circuit intoaction without ringing the other bells on the same circuit.

The invention is embodied in an apparatus in which an automatic switchat each signalstation shall be operated under certain conditions of thecurrent to close a branch circuit in which its signal-bell magnet isplaced, therequired conditions to closethe said branch circuit beingdifferent at each switch and signal, so that one only is operated at atime.

It also consistsin a novel key-board, by which the proper current may besent to operate any of the signals, as desired.

As herein shown, the circuit is adapted for four signals, two only ofwhich are shown, and the currents used are of two different strengths,each capable of being sent in either direction, thus making the fourdifferent conditions of current required.

The automatic switches each consist of an electro-magnet provided with apolarized and neutral armature, and suitable contact-stops for each ofthe said arrnatures, which are so arranged and adjusted that when theweak current is passing the neutral armatures will remain on their backstops, but when the strong current is passing they are drawn againsttheir front stops; also, when the current of either strength is passingin one direction the polarized armature is against one stop, which maybe called its positive stop, and when in the other direction against itsnegative stop. As the switches are or may be all alike, the armatureswill assume the same positions in all, and each signal-bell magnet willbe in circuit with one stop of the polarized and one stop of the neutralarmature of its switch, but each different bell-magnet will be incircuit with a difierent pair of stops from all the others, so that thecircuit will be completed by the armatures between the said stops foronly one bell-magnet with any one position of all the switches.

The key-board is provided with three keys for operatingthe four bells,suitably connected with a battery and the main-circuit line, so that onewhich may be called the positive key puts the battery on the line inone, and another or negative key puts it on in the other direction.while the third key, when used with either of the others, serves toremove or open a portion of the battery, and so send a weaker current inthe required direction.

Figure 1 is a plan view showing on the left hand the battery andkey-board of the signaloflice, and on the right hand two signal-stationsprovided with the automatic switches and signal-bells, and Fig. 2 is afront view of the key-board.

The key-board or transmitting device is provided with three keys, a b 0,(shown as placed side by side,) each provided with back stops, withwhich they form electrical contact when not depressed, and with anvils,with which they may form electrical contact when .de-

pressed. One of the keys (preferably the middle one, 0) may be calledthe dividin g-key, as its function is to divide and remove a portion ofthe battery, and thus control the strength of the current. One of thecontact-pieces of this key (shown as the back stop, 01) is connected bythe wire 2 with one extreme pole of the battery B-for example, thepositive one-and the other contact-piece-namely, its anvil cis connectedby wire 3 with a similar pole at an intermediate point in the battery,and the key itself is connected by wire 4 with the back stop, f, whichserves for bothkeys a b, which may be termed the positive and negativekeys, as their function is to connect the positive and negative poles ofthe battery to the line-circuit. The anvil 9, common to both keys to b,is connected by wire 5 with the other or negative pole of the battery.The key a is connected with the ground, and the key I) with theline-wire 6, and in practice may be connected with .any desired one of anumber of circuits by any suitable switch apparatus.

It will be seen that by the arrangement described the back stop, f, ofthe keys at b is connected by wires 2 and 4, and key 0, when notdepressed, with the positive pole of the whole battery, and by wires 34, and said key c,when depressed, with a positive pole of a portion ofthe battery, so that the only function of the key 0 is to remove aportion of the battery and weaken the current. It will thus be seen thatthe back stop of the keys a b is always connected with one and theiranvil with the other pole of the battery, and consequently when the keya, in connection with the ground, is alone depressed to the anvil g, thenegative pole of the battery is grounded,while the positive pole isconnected by back stop,f. and key b (not depressed) with the line,whileif the key I) alone is depressed it connects anvil g and negative poleof the battery to line and the positive is grounded through the backstop, f, and key a, (not depressed.) lVhile the key 0 is depressed thatportion of the battery between the wires 3 and 5 will be put to line inone direction by the key a, and in the other by the key I).

The line-wire 6 passes on to and through the coils of the differentswitch electro-magnets h i, and finally to the ground, which completesthe circuit to the key a, as before described. The switchelectro-rnagnets are each provided with polarized tongues l, pivoted at7 to vibrate in either direction, the free end being provided with afinger to form contact with one of the stops at n, according to thedirection of the current through the coils of the magnet. For example,if the key a is depressed to send the current from the positive pole,the tongues I will be connected with the stops m, which may be calledpositive stops,and when the key I) is depressed the said tongues I willbe held connected with the negative stops n. The magnets h t are alsoprovided with neutral armatures o, with retractors p, adjusted to retainthe armatures against their back stops when the portion of the batterybetween the wire 3 and 5 alone is in circuit, but to allow the armaturesto be drawn to their front stops by the whole battery B.

The electro-magnets q r of the signal-bells are each placed in abranchcircuit around the switch-magnets h i, one electrode of the saidbell-magnets being connected by wire 8 with the main wire 6 on one sideof the switchmagnet, and the other electrode by wire 9 with one of thestops of the neutral armature 0-two bells with the front stop and twowith the back stop-the circuit being continued by the armature 0 when incontact with the said connected stop and metal of the switch with thetongue 1, and one of the stops at a connected by wire 10 with the mainwire 6 beyond the switch-magnet.

In one of the switches of the pair of bells connected with the frontstops and one of the pair connected with the back stops the stop on isconnected with the wires 10 and 6, and in the other switch of each pairthe stop a is so connected. One bell of each pair is shown, and

they may be called Nos. 2 and 3, No. 1 (not shown) being connected, likeNo. 2, with the front stop of the armature 0, but with the other orpositive stop, m, of the tongue I, and No. 4 being like No. 3, butconnected with stop it, instead of m. The bells 1 and 2 are, preferably,vibrators, the wire 8 being connected to their insulated armature backstops; but the bells 3 and 4 may be single-tap bells.

The switches are shown in Fig.1 as they will be when the keys 0 and aare depressed, the circuit of bell No. 3 being complete to operate thesaid bell. The circuits of the other bells are broken, that of N o. 4 atl n, and those of Nos. 1 and 2 between 9 and 0. A tap is given each timethe key a is depressed, and care must be taken that the key a does notreach its anvil before the key 0 reaches its anvil e.

In practice it will be well to hold the key 0 depressed, and tap withthe key a to operate bell No. 3, or key I) for bell No. 4.

If the switches are in the position shown in Fig. 1, and the key (0alone is depressed to ring the bell No. 1, there will be danger thatbell No. 3 will give a tap before the armature 0 is moved to break itscircuit, and for this reason it is preferable that the bells 1 2 shouldbe automatic circuit-breakervibration bells, the keys to I) beingdepressed but once.

It is obvious that bells rung by a magnetoelectric current may also beemployed in the same circuit with the switches.

I am aware that relays or switches having polarized and neutralizedarmatures adjusted to respond to currents of different polarity andstrength have been employed to control different local circuits, and Ido not claim such apparatus, broadly.

The arrangement of the signals in branches of the main circuit, insteadof in an independent local circuit, is simple and economical, andobviates the necessity of maintaining signaling-batteries at differentstations or points of the lines.

I claim- 1. In a telephone-signal apparatus, a series of automaticswitches in a main circuit, and branches of the said circuitcontrolledthereby, containing signal-operating elcctro-magnets, each of the saidswitches being composed, essentially, of aneutral and a polarizedarmature, each controlling a closing-point in the said branch circuit,the said neutral armatures being adjusted difi'erently, and thepolarized armatures being of unlike polarity in different switches,whereby only one of the said switches is properly operated to close bothpoints of the branch circuit by a current of given strength andpolarity, as and for the purpose described.

2. Adividing-key having one stop connected with a pole of a batteryconsisting of more than one cell, and its other stop connected with asimilar pole of an intermediate cell of the battery, combined with twoother keys having a common back stop connected with In testimony whereofIhave signed myname 10 the first key, and through it with one pole of tothis specification in the presence of two subthe whole or a portion ofthe battery, and a scribing witnesses.

common front stop or anvil connected with the other pole of the battery,one of said keys JOHN MCCOY being connected with one extremity of theWitnesses:

line an 1 the other with the other extremity JOS. P. LIVERMORE,

thereof, or ground, substantially as and for the N. E. O. WHITNEY.

purpose described.

